This invention relates to a device for optical control of a beam-scanning antenna and more particularly to a device in which its optical means are employed for controlling the radiation pattern of a radar antenna which transmits in the 1-12 GHz frequency band, for example. The proposed device performs the function in particular of angular scanning of the radar beam by controlling the phase of each element of the antenna.
The invention is applicable to electronic beam-scanning antennas in which each radiating element is controlled electronically and independently in order to produce a scan for the antenna. Electronic scanning makes it possible to modify the position of the scanning beam. Beam scanning has to be performed at a high rate in comparison with the repetition frequency of the radar. In order to obtain rapid scanning, the known method of electronic control employed in the prior art consists in producing action on the respective phases of the controls of the various radiating elements It is therefore necessary to carry out a rapid phase-control operation. To this end, a microwave phase-shifter is associated with each antenna element. These phase-shifters have the disadvantage of high current consumption and are also cumbersome.
In the device for optical control of antenna elements in accordance with the invention, it is possible to avoid the use of these microwave phase-shifters.